1. Field of the Invention
This invention generally relates to resistance based exercise equipment and more particularly to a spring connector for connecting a coil spring between members in a spring biased resistance exercise machine such as in a Pilates chair and reformer.
2. Description of Related Art
Today, many types of exercise equipment are available and used for fitness and/or medical reasons to burn off undesired calories, to improve cardiovascular ability, to tone or strengthen muscles, or to improve flexibility, balance, posture, etc. No matter what the desired end goal of a user of exercise equipment may be, almost all types of exercise equipment aid the user to achieve his or her desired goal by exerting some form of adequate and effective resistance against repeated bodily movements of the user.
Many of these exercise devices utilize elastic resistance members such as coil springs. A hook is often used to connect each of the two ends of the coil spring (or generally a force resisting mechanism) between a movable and a fixed location on the exercise equipment.
A reformer is one such exercise device that is basically a rectangular frame that sits on a floor and constitutes or carries a pair of stationary parallel rails or tracks. A rollable carriage for supporting a user's body is mounted on the rails for movement toward and away from one end, the foot end, of the frame. The carriage is typically elastically biased toward the foot end of the frame by one or more coil springs attached to the carriage and to an anchor bar near the foot end of the frame.
Another exercise apparatus is a Pilates combo chair. The chair is a boxlike structure that has a pair of spring biased pivot arms attached thereto. The box structure is designed to rest on a horizontal surface such as a floor. Each of the pivot arms has one end fastened to an inside wall of the box. The free end of the pivot arm has a foot step/support pad mounted thereon. A user typically stands on the floor and steps or presses downward on the step pad at the free end of the pivot arm with his or her foot. Alternatively, the user may sit on the box and with foot or hand rotate the arm downward against tension provided by one or more coil springs attached between an anchor point on the arm and an anchor point inside the box in order to perform various exercise movements.
Each coil spring has a generally cylindrical spiral outer shape, with tapered coils at each end. One end of each coil spring has a bent rod connector in the form of a hook. The other end of each coil spring typically also has a hook that must be inserted into the eye of an eyebolt fastened to an anchor point.
Each end of the coil spring carries a bent rod connector in the end of the coil forming either the hook or an eye at its distal or head end. The bent rod connector, typically made of spring steel, has a frustoconical metal stopper grommet threaded onto its foot end. The end of the foot end of the bent rod threads through the end coils of the spring and is then squashed into a generally rectangular shape that then locks the metal grommet onto the foot end of the bent rod, inside the end of the coil spring. Several coil turns at the end of the coil spring have a reduced diameter, giving the ends of the spring a conical shape. These turns engage the grommet to hold the foot end of the bent rod connector in the end of the coil spring. During extension and contraction of the spring, some noise may be generated by the expanding coils of the spring interacting with the foot end of the hook as the spring approaches or departs from a relaxed condition. Such noise may be distracting to the user of the exercise apparatus. Thus there is a need for a device that securely but silently connects such a hook or other fastening member to an end of a coil spring in an exercise apparatus.